After being discharged from the military, McIntosh worked as a pathology assistant at the Boston City Hospital. Moving to New York City, he became a medical intern at NewYork–Presbyterian Hospital and a pediatric intern and resident at the Babies Hospital (now Morgan Stanley Children's Hospital). He worked in private practice in New York from 1923 and 1927, before relocating to Baltimore to take up a position at the Johns Hopkins Hospital under the pediatrician Edwards A. Park. In 1930, he returned to work at NewYork–Presbyterian, where he was appointed chief of pediatrics at the Babies Hospital and made a professor at Columbia University.[1] He married Millicent Carey McIntosh in 1932; the couple had five children.[3]
McIntosh was a pediatric generalist, but as the director of pediatrics at the Columbia University College of Physicians and Surgeons, he assembled a department of noted pediatric subspecialists; these included Dorothy Andersen (pathology), Hattie Alexander (infectious disease), William Silverman (neonatology), and John Caffey (radiology). McIntosh published numerous research articles on congenital malformations, chaired a council on rheumatic fever, and was involved in several international congresses on poliomyelitis. He and L. Emmett Holt, Jr. (son of Luther Emmett Holt) were the editors of select editions of the textbooks Holt's Diseases of Infancy and Childhood (10th and 11th editions, 1933 and 1940) and Pediatrics (12th and 13th editions, 1953 and 1962). In 1953–1954, he served as president of the American Pediatric Society and in 1961, he was awarded the John Howland Award, the highest honor given by the society.[1]
McIntosh retired from medical practice 1960 and became a professor emeritus at Columbia.[2]
